Re: pg_control is missing a field for LOBLKSIZE

On 06/04/2014 10:03 AM, Tom Lane wrote:
> I just chanced to notice that if someone were to change the value for
> LOBLKSIZE and recompile, there'd be nothing to stop him from starting
> that postmaster against an existing database, even though it would
> completely misinterpret and mangle any data in pg_largeobject.
>
> I think there ought to be a guard for that, for exactly the same reasons
> that we check TOAST_MAX_CHUNK_SIZE: correct interpretation of on-disk
> data requires that this value match the original database configuration.
>
> Obviously it's too late to do anything about this in existing branches,
> but I propose to add a field to pg_control after we branch off 9.4.
>
>

If we did an initdb-requiring change for 9.4 could we piggy-back this
onto it?

cheers

andrew